Cambridge engineers moot 'silent' plane

A research group at the University of Cambridge is working on a radical new aircraft design it says could eventually reduce the noise pollution in areas around airports to virtually nil.

The silent aircraft initiative, a joint research project between Cambridge and MIT, began in 2003. The stated aim of the group is "to discover ways to reduce aircraft noise dramatically, to the point where it would be virtually unnoticeable to people outside the airport perimeter".

The BBC reports that the UK's Luton airport is now planning to partner with the group in actually building the jet some time in the next ten years.

While most of the noise from planes is caused by their engines, the physical design can also make a huge difference. For example, on landing, at least half the noise is due to the airframe, the researchers say. Among other things they have been looking at ways of slowing a landing plane more quietly.

A plane built to their design would be virtually inaudible once it had left the airport, they said.

The design is a departure from the traditional cigar shaped plane we are all familiar with. Instead it is essentially a flying wing, with its engines mounted on top of the plane, to direct noise away from the ground. This also reduces the mount of drag they contribute to the plane in flight.

Work is still needed on the design - a plane like the one illustrated, for example, would suffer from too-high loads on the fan blades that bring air into the engines. Engineers are still working on that problem, but have already worked out a variable geometry exhaust system that reduces the impact of a large exhaust area on weight and fuel efficiency.

The researchers expect their design to be completed in the next 12 months, the BBC says, and with Luton's backing, to have a test vehicle built within the next ten years. ®